In my 20+ years with Amex I have only had 1 hard pull over a dozen+ personal & biz (not corporate) cards. Of course in the application you do agree to authorizing a hard pull but Amex very rarely does these and rather uses an internal ranking system for cardholders. That scoring is based on spending & payment history with Amex, credit report soft pull data and current economic factors including those impacting your employment industry.
I find Amex Biz card approvals to be far easier than other banks for existing cardholders.